(a) Field of the Invention
The present invention relates to a decoding method and device, and in particular, it relates to a decoding device and method for a multi-input multi-output system.
This work was supported by the IT R&D program of MIC/IITA. [2006-S-014-02, Development of IEEE 802.11n Modem & RF Chip-sets with Data Rate 200 Mbps].
(b) Description of the Related Art
The multi-input multi-output (MIMO) system is a core technique for the wireless digital communication system, and a plurality of corresponding transmitting/receiving schemes have been researched. In general, a method for a transmission part to process signals includes the Bell Labs layered space time (BLAST) method, and a receiving method for a receiving part to process signals includes a linear detection method and a nonlinear detection method.
The linear detection method includes the zero forcing (ZF) method and the minimum mean square error (MMSE) method. Also, the nonlinear detection method includes the maximum likelihood (ML) detection method and the successive interference cancellation (SIC) method.
Regarding the nonlinear detection methods, the ML method improves performance by inputting symbols that are transmittable by transmit antennas and selecting the input that has the minimum square Euclidean distance. However, the ML method exponentially increases complexity according to the number of transmit antennas and the order of modulation.
Also, the SIC method increases performance by detecting and eliminating a channel that has a great signal to interference plus noise ratio (SINR). However, an ordering process for acquiring the best performance is required so as to use the SIC method.
In the theoretical information viewpoint, the SIC method is the best receiving algorithm for achieving channel capacity, but it requires a large amount of decoding delay since it needs to perform sequential interference cancellation. Further, the ML method generates good performance for the frame error rate, but it is difficult to apply to a real receiver because of its great operation complexity.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.